F12 rear mesh vent paint bubbling....a primer

Hello Friends,
Now that I believe I have sorted out my rear hatch leak, I wanted to turn my attention to the rear mesh vents in a bid to PREVENT what I believe is inevitable for every F12....paint bubbling.

Putting the car on the lift and removing wheels and rear well liners revealed a few interesting things. The drivers side mesh vent cannot be accessed from in the wheel well, you must go in through the trunk (image 1 and 2). There is a solid bulkhead blocking access to that rear quarter panel "chamber".

On the passenger side, the story is different (Image 3 and 4). The evap/purge canister is mounted in that "window", and it must be removed to be able to access the mesh vent.

The other "interesting thing" about these mesh vents is that infuriatingly so, they appear to have NO practical purpose.
Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login

 

Removing the driver's side mesh was a real pain. You must remove the interior trims from the trunk, including the leather panel that runs along the edge of the hatch lip. These trims are fragile and very tightly wedged into their respective locations so be careful. The leather panel fastens by means of a single 8mm bolt at the top edge of the trim, two snap fasteners, and a t20 torx screw that is hidden UNDER the rear trunk trim panel.

To access the actual mesh, you must remove the plastic drainage tray that bolts under the mesh. This drainage tray empties to the outside via a drain tube that you saw in the previous post. The rubber grommet of the tube can just be worked loose and then pushed INWARD into the quarter panel chamber. It will need to be free to remove the drain tray from inside the trunk. The drain tray is fastened to the body by way of six or seven 8mm bolts. You have to practically be spiderman to do this stupid job, and will have to remove them by feel. Once the drain tray is removed, the mesh actually anchors to the body by way of five 8mm bolts. Same story.

Image 1 shows the ALREADY RUSTING steel mesh.

At this point I turned my attention to the body lip where corrosion usually is seen, and much to my horror I saw the beginnings of bubbling on my precious car. If you look carefully at Image 2 the red arrow shows the beginnings of "bubbling". To the right and left of the arrow are white abrasions on the undersurface of the body that are from contact with the mesh. You can also see another bubble to the left of all of this, but honestly it is on the undersurface of the lip and I believe its probably a paint drip.

Inspecting around the entire edge where the mesh meets the body showed several other areas of abrasion from the mesh. (Image 3)
Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login

 

Thankfully, this damage is at a very early stage and I believe I can impact it positively. My plan will be to remove the corrosion bubble, and apply SEM self etching primer to the bare aluminum. After taping off the area, I used a razor blade to remove the paint over the bubble, which crumbled away. (image 1). I then cleaned all areas of abrasion with denatured alcohol and applied the SEM primer (Image 2) Once this dries, I will apply touch up base color and touch up clear to all of the areas. These areas are so small that I need to use a microbrush to do it. All of the other 'points of contact' that I found will receive the same treatment.

The next step will be to fully strip the steel mesh, reprime, and repaint it. I had to do the same thing on my 550.

I'm in the process of correcting the car's finish, and once this is done I will ceramic coat it with Kamikaze products. I will also glass coat the inner lip where the touch up was applied.

Once all of this is done, I will reinstall the mesh with plastic spacers that drop it away from the body by 1-2mm. I think that is all I will need to ensure that this never becomes an issue again.
Image Unavailable, Please Login Image Unavailable, Please Login

 

Thanks for the primer (no pun intended)
Very helpful

 

If you have corrosion under the paint then there is no touching up that will be a permanent fix. The grills have to be replaced for new as well. You should have this handled by the dealer IMO. If they do the repair it will be warranted. If you do it your on your own which doesn't make much sense to me.

 

They reused the original black mesh on my Ferrari authorized repair.

They also put some bonding agent in the edges where the outer panel and the subpanel meet as pointed out by the red arrow.

All corrosion spots were sanded down to the metal.

As for the source of galvanic corrosion we know that the black mesh is steel and the outer and subpanel are aluminum so any moisture where they touch can act as a catalyst if there isn't enough of a paint barrier.

Could you test the screws to see what material they are? I've heard stainless should be ok or low carbon.

 

I'm not the poster so sorry don't know.

 

Does the corrosion continue if the galvanic effect is removed?

Also - I think the dealer sprays the whole panel, which to me seems excessive in this case at least.

 

It's my understanding that the dealer does what is necessary to complete the factory repair if they decide to cover it.

 

Can you expand on this please. Curious to know what lead you to this conclusion?

 

Galvanic corrosion is the transfer of electrons from dissimilar metals, in this case steel and aluminum. Water or moisture acts as a catalyst to speed up the process. Paint acts a barrier to prevent electron transfer.

As far as I understand it, removing the catalyst will slow down the corrosion since electron transfer is slowed. But humidity in the air, washing your car, etc are things you can't stop.

Ferrari seems to think a nice thick coat of primer and paint is the solution and it can prevent electron transfer, but the physical rubbing of the mesh against the painted aluminum edges wears down the paint barrier and thus the barrier is rendered ineffective. That's why the spacers are necessary to prevent this from happening.

 

I removed the other mesh last evening, and I find no evidence of bubbling on the passenger side of my vehicle. There are a few abraded spots underneath the lip, but no corrosion has occurred to the best I can see.

Regarding the vents themselves, in my experience when these vents are present there is usually some reason. For example, in my 550 there was a quarter panel vent underneath which lived the gearbox oil cooler. There is no such machinery or equipment in either one of the F12 quarter panels. The only thing I can come up with is that these vents serve to decompress air pressure inside the wheel wells. So I guess it’s possible there is an aerodynamic reason for their existence, but otherwise I don’t see one.

For the poster who suggested that nothing I did was going to make any difference and that I should just let Ferrari fix it, no. I do not want the rear quarter panel of my car resprayed to deal with a tiny spot of bubbling that is the size of the head of a pin. I scraped the area of corrosion down to bare metal, and re-primed the surface prior to applying paint. This is exactly what any body shop would do. I am just lucky that it is such a small area that I can do this without it being apparent. I would prefer to keep my car original, and it’s paint is likely going to be very difficult to match.

I have a two-year power warranty on the car. I will keep a careful watch over this spot, and should it recur or worsen I will have them fix it. However, my bet is that the actions that I take here will prevent any further damage from occurring.

 

Just so you know you would be covered by the 2 year extended warranty by Ferrari. They originally tried to get me to buy this to cover the paint work.

 

Yes indeed, this was one factor in my decision to get the warranty. However, I am well aware of Ferraris habit of abandoning customers when problems arise, so I felt that the warranty would offer me a little bit of security for the “next thing” that might come up with the F12.

 

Paint is only guaranteed for 36 months regardless of warranty. Power warranty is also the lowest form of coverage as even leaks are not included. The longer you wait to address the issue with the dealer after the sale the less interest the factory has in addressing it. Unless, of course, you stay on their radar with recurring car sales, warranties and services. When addressed by the factory they will refuse to do a spot repair due to the expected longevity of that kind of repair. If you have any questions speak to your service manager who will consult the factory area rep. on your behalf. Best.

 

my corrosion wasn't evident until about 2 months into ownership. if you really want to avoid the conditions which i think led to my development it's humidity and water.

the worst thing you can do is drive it in a heavy rain then pull into your garage wet and let it sit there overnight, wet, humid garage. if possible don't drive it in the rain or dry it off when in the garage with towels and a leaf blower around the mesh. same with car washes just make sure it's bone dry in the mesh area after.

i think it's prolonged water exposure over an hour that is the real problem.

 

Absolutely brother! Great advice. My garage is air-conditioned, and the car does not get driven in the rain. In addition, a leaf blower is an integral part of any car wash process to prevent marring.

 

It took me a little bit to get the job done, but the vents are finished. Once the grilles were stripped, sanded, and repainted, I fitted nylon spacers in a trial and error fashion to drop the grill height 1-2mm away from the quarter panel lip. Using two of these spacers at each screw site (Image 1) I was able to get a good fit. Two of the pictured spacers on top of each other measure 3.15mm thick.
This is what the grilles look like once the spacers are placed (Image 2).

Images 3,4 and 5 show the grille fastened back into place in the quarter panel, with an equal gap around all edges. It takes a little bit of jimmying to get all angles equal.

Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login

 

Well. I’ll say. I had it on my car before I bought but didn’t know it. The owner had it repaired under warranty I think in Texas where the car lived. I can post the pictures of the work. Perfect with no evidence of anything. Move the car to central Florida and about seven months later, recurred. Only I didn’t know at the time it recurred, to me it simply occurred. Steve at Boardwalk didn’t have it down as being done prior.

Car went to Miami to the authorized shop and was done with the new part and insulation etc. Now seven months later it’s perfect. What’s interesting is the other mesh areas do not get the same problem at all.

You know when you say to not get the car wet and not drive in the rain, I say just drive it and deal with it. My cars are cared for, stored in air conditioning, and not abused. Things will happen. That’s what the dealer is for.
I’ll find the pictures.
ScottS

 

what new parts? i asked specifically about a replacement black mesh and they said there wasn't one. ideally if they made one out of aluminum that would solve everything.

 

Scott what was the down time for the repaint?

 

I finally got round to replacing both the vents.
I replaced both with ones that have been fabricated by Ferrarichat member pezrod
aluminium mesh on a carbon fiber frame.
a perfect fit, and peace of mind that this will eliminate the issue of electrolytic corrosion.
The OEM mesh is going to have to be rectified on all F12s.
in the future I am sure its is going to be a question that's going to be asked by potential buyers.
during the fitting, I realised how erratically, haphazardly, ill thought out the fittings and construction of Ferrarris are. Poor bolts and screws that deform on touching, non sensical use of 5 or 6 different types of fixtures when one two would do.....really frustrating.
I would highly recommend getting a trustworthy garage to do the job, as access to some of the bolts is back braking....it took me a 7hrs to do the job.
Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login

 

Thanks for the detailed write ups and illustrations/pics.

Im still stuck on the fact that they seem to have no function. It's purely aesthetic??

 

Not necessarily. They have a tube leading to the rear wheel wells, so they're must likely for bleeding off increased air pressure that develops in the rear wheel wells and can cause unwanted lift at high speed. Given the small size of the tube I'm not sure how effective it is in the real world, but I'm betting that was the design.

 

the tube is there as a water drain...
where the tube ends is different on both arches.
sequence: tube end, wheel arch trim, wheel arch space.
nothing to do with pressure equalisation.
purely aesthetic.